login-with-chatgpt

Login with ChatGPT

SDK for "sign in with your ChatGPT account". Users authenticate through OpenAI's device flow; your handler keeps the tokens and proxies Responses-style calls to the ChatGPT-backed Codex endpoint. The browser only ever holds an HttpOnly session cookie.

Rules: read before writing code

1. There is no API key. Auth comes from each user's ChatGPT session. Never add OPENAI_API_KEY, never call api.openai.com directly for this flow. Requests go through the app's own /api/chatgpt/responses proxy or a server route built on auth.proxyFetch(request).
2. Discover before selecting a model. Availability is per account and plan. Call await chatgpt.listModels() (browser) or await auth.getModels(request) (server), then pick from that result. A hardcoded allowedModels guardrail is fine; assuming one model exists for every signed-in account is not.
3. Tokens stay inside the handler by default. Don't build endpoints that return tokens to the client. Normal app code should use /responses, /models, or auth.proxyFetch(request). Raw token export requires the explicit dangerouslyAllowTokenExport escape hatch.
4. Consent cannot be removed. The widget always shows a consent step before OpenAI's verification page. Custom UIs must render equivalent consent before calling login().
5. Production needs a stable secret and a shared sessionStore. The defaults (ephemeral secret, in-memory store) log everyone out on restart and break across serverless instances.

Packages

bun add @opencoredev/loginwithchatgpt-server @opencoredev/loginwithchatgpt-react @opencoredev/loginwithchatgpt-ai ai @ai-sdk/openai

Server handler

One handler owns everything under basePath (default /api/chatgpt). It is written against Web-standard Request, Response, fetch, and crypto.subtle, so use it in runtimes that provide those APIs.

// Next.js: app/api/chatgpt/[...lwc]/route.ts
import { createChatGPTHandler } from "@opencoredev/loginwithchatgpt-server";

const auth = createChatGPTHandler({
  secret: process.env.LWC_SECRET, // openssl rand -hex 32
  responsesProxy: {
    allowedModels: ["gpt-5.5", "gpt-5.4", "gpt-5.4-mini"],
  },
});

export const GET = (request: Request) => auth.handler(request);
export const POST = (request: Request) => auth.handler(request);

// Bun
Bun.serve({
  routes: {
    "/": index,
    "/api/chatgpt/*": (req) => auth.handler(req),
  },
});

Key options: basePath, secret, sessionStore (any get/set/delete key-value store), cookieName, cookie, sessionTtlMs (30 days), defaultModel ("gpt-5.5"), enableResponsesProxy (false also disables /models), responsesProxy (allowedModels, maxRequestBytes 40 MiB, rateLimit default 30/min/session), allowedOrigins (cross-origin CSRF allowlist).

Server helpers on the returned handler (all read the session cookie):

• auth.getSession(request) → { status, user? }; no upstream call.
• auth.proxyFetch(request) → request-scoped fetch for custom server AI routes without exposing raw bearer tokens.
• auth.getModels(request) → account's model slugs or undefined.
• auth.dangerouslyGetTokens(request) → raw-token escape hatch; requires dangerouslyAllowTokenExport.

React sign-in

"use client";
import { LoginWithChatGPT } from "@opencoredev/loginwithchatgpt-react";

<LoginWithChatGPT
  consent={{ appName: "Acme" }}
  onAuthenticated={(user) => console.log("connected", user?.email)}
/>;

The widget handles the full flow: consent popup → OpenAI verification → code copy → polling → signed-in chip with Disconnect. Restyle via the injected .lwc-* classes, or pass a children render function for a fully custom UI (then render your own consent and use openLoginWithChatGPTConsentPopup()).

For custom UIs, useLoginWithChatGPT({ basePath?, pollIntervalMs?, ... }) returns { status, user, userCode, verificationUrl, login, logout, copyCode, reopen, isAuthenticated, isPending }. status is one of loading | unauthenticated | connecting | pending | authenticated | expired | error.

Streaming with the AI SDK

Browser proxy provider, with credentials injected server-side from the cookie:

import { createChatGPTProxyProvider } from "@opencoredev/loginwithchatgpt-ai";
import { streamText } from "ai";

const chatgpt = createChatGPTProxyProvider(); // { basePath } if not /api/chatgpt

const models = await chatgpt.listModels(); // throws ChatGPTProxyError; status 401 = signed out
const model = models.includes("gpt-5.5") ? "gpt-5.5" : models[0];

const result = streamText({ model: chatgpt(model), prompt });

Server proxy provider for your own AI route:

import { createChatGPTProxyProvider } from "@opencoredev/loginwithchatgpt-ai";
import { streamText } from "ai";

export async function POST(request: Request) {
  const chatgpt = createChatGPTProxyProvider({
    fetch: auth.proxyFetch(request),
  });
  const { prompt } = await request.json();
  return streamText({ model: chatgpt(), prompt }).toUIMessageStreamResponse();
}

Models support streamText, generateText, tool calling, structured output, and file attachments via standard AI SDK messages. Images are a first-class provider API: use chatgpt.images.generate() for prompt-to-image and chatgpt.images.edit() for edits, multiple references, masks, input fidelity, custom size, quality, format, compression, background, multiple outputs, and partial-image callbacks. Both use the signed-in user's ChatGPT plan through /responses; do not add an API key. Embeddings and audio are not provided.

Per-request tuning headers on POST /responses: x-login-with-chatgpt-reasoning-effort (none|low|medium|high|xhigh) and x-login-with-chatgpt-service-tier (auto|default|flex|priority|fast).

HTTP routes (relative to basePath)

Non-GET routes enforce Origin-based CSRF: same-origin or allowedOrigins only. Split frontend/backend deployments also need SameSite=None cookies, credentialed fetches, and CORS headers (see the cross-origin guide).

Production checklist

• Set LWC_SECRET (stable across deploys; rotation logs everyone out).
• Use a shared sessionStore (Redis/DB). MemoryStore is dev-only.
• Set responsesProxy.allowedModels; pass a shared rateLimit.store when running multiple instances.
• HTTPS with X-Forwarded-Proto forwarded so the cookie gets Secure.
• Log /responses metadata (session id, model, status, duration), never prompts or attachments.

Errors

ChatGPTAuthError (from core) has .code, .status, .body. Notable codes: refresh_token_invalid (session dead; handler deletes it and reports expired; detect with isRefreshTokenInvalid(error)), not_authenticated, token_refresh_failed (retryable), models_request_failed. The browser provider's listModels() throws ChatGPTProxyError with .status. HTTP errors from /responses: 401 not_authenticated, 403 model_not_allowed / origin_not_allowed, 413 responses_request_too_large, 429 rate_limited (+ retry-after).

Docs

Full docs live in the repo under docs/content/docs/ (quickstart, concepts/security, guides/production, reference/*). The docs site also serves /llms.txt and per-page markdown at /llms.mdx/docs/<path>/content.md.